From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L2721-0005bC-U9 for qemu-devel@nongnu.org; Mon, 17 Nov 2008 11:32:57 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L271w-0005aw-Dk for qemu-devel@nongnu.org; Mon, 17 Nov 2008 11:32:57 -0500 Received: from [199.232.76.173] (port=36005 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L271w-0005at-94 for qemu-devel@nongnu.org; Mon, 17 Nov 2008 11:32:52 -0500 Received: from yw-out-1718.google.com ([74.125.46.156]:34967) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1L271t-0004ZQ-8c for qemu-devel@nongnu.org; Mon, 17 Nov 2008 11:32:51 -0500 Received: by yw-out-1718.google.com with SMTP id 6so1007841ywa.82 for ; Mon, 17 Nov 2008 08:32:42 -0800 (PST) Message-ID: Date: Mon, 17 Nov 2008 10:32:41 -0600 From: "Hollis Blanchard" Sender: slightlyunconventional@gmail.com Subject: Re: [Qemu-devel] Re: Status on ARM host cpu In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200811141415.51702.paul@codesourcery.com> Reply-To: hollis@alumni.cmu.edu, qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Sat, Nov 15, 2008 at 9:12 AM, Steffen Liebergeld wrote: > Hi Paul, > > Paul Brook schrieb: >> On Friday 14 November 2008, Steffen Liebergeld wrote: >>> Hi, >>> >>> I am currently researching of whether or not it is feasible to port kqemu >>> to the ARM platform. The website says qemu on ARM hosts is in >>> "testing"-state. Does that still apply to the latest svn-Version? >> >> Should just about work, though you should expect bugs. > >> However I advise using KVM and not kqemu. KVM has already been merged to >> upstream kernels, and the chances of getting another hypervisor interface >> merged are approximately zero. > > KVM is not an option for me (and is not available for the ARM-platform). > > I plan to port kqemu for the ARM-platform. Do have any estimates, for how much > work would be needed to adopt the kqemu-Interface of qemu (which is > x86-centric) to ARM (ignoring the effort needed to port the > kqemu-kernel-module)? To expand on what Jan said, I've implemented KVM on PowerPC 440 core, which has no hardware virtualization support. I expect you're in the same situation on ARM. Basically you execute most guest instructions natively in hardware, running in user mode. When the guest kernel attempts to perform a privileged operation, you trap to supervisor mode and emulate it. (Optionally, you can also patch the guest to prevent it from attempting that operation in the first place.) This is very feasible given the KVM interface -- the 440 support is already working and merged upstream. I would strongly recommend working with KVM instead of kqemu, if for no other reason than KVM has a development community which can help you, and kqemu doesn't. -Hollis